Notarized paperwork says that one of Capone’s booze runners stole the gun from his golf bag in 1930.

“That’s why it is in an old vintage Spalding golf ball box,” Miedema explained.

The booze runner then gave it as a gift to his half-brother. The half-brother sold it in the 1980s to a man in East Grand Rapids for $500. It changed hands a few more times before ending up in the hands of the consignor, a West Michigan collector.

Further bolstering the possibility that the gun’s owner was Capone is a 2004 letter from Smith & Wesson confirming the gun was shipped out to be sold in September 1924, six years before the supposed golf bag theft.

“We’re very confident that it is his gun. There’s nothing that proves that it’s not his gun,” Miedema said.

It’s the type of thing he’s never seen at the auction house before.

“Nothing to this type of uniqueness where the actual owner is someone as big as Al Capone was,” he said.

He said the gun is worth thousands regardless of whether it was Capone’s.

“It is a collectible gun even without the uniqueness behind it,” Miedema said.

The online auction at SSLFirearms.com runs from 8 a.m. to 8 p.m. on Jan. 9.

“We’re really going to leave the price up to what the high bidder decides it’s worth,” Miedema said.